The Thailand HIV/AIDS and Infectious Disease Clinical Trials Unit (THAI CTU) Is the renamed renewal of Chiang Mai University HIV/AIDS Clinical Trials Unit- Sirisanthana, Thira (Grant# U01 Al 069399, Feb 2007-Jan 2014), which expands beyond the Chiang Mai University Research Institute for Health Sciences (CMU-RIHES) to add the experience and resources of another major HIV research institution: the Thai Red Cross AIDS Research Centre (TRC-ARC), affiliated with Chulalongkorn University. The aim of the THAI CTU Is to collaborate with five Clinical Research Networks established by NIAID, NIH under RFA-AI-12-001, -004, -008, -011, and -012, in coordinating and executing clinical research in Thailand and the neighboring region to expand knowledge and improve treatment and prevention of HIV and related Infectious diseases. It also aims to assist the CRNs In refining their research agendas to meet the needs, priorities, circumstances, and sensitivities of low- and middle-income countries in hosting research studies, so that findings are of utility fo preventing and treating HIV and related conditions both universally, as well as in the country of research. Located in the cities of Chiang Mai and Bangkok, Thailand, the THAI CTU is led by Co-Principal Investigators Suwat Chariyalertsak and Kiat Ruxrungtham, plus P. Phanuphak, T. Sirisanthana, K. Supparatpinyo, G.J.P.(F) van Griensven, V. Sirisanthan, A. Avihingsanon, T. Puthanakit, and K. Srithanaviboonchal. It is comprised of four Clinical Research Sites which will implement clinical and related HIV studies on maternal, pediatric, and adult therapeutics, on topical microbicides to prevent HIV transmission, on Integrated population-based prevention strategies, and on vaccines. After appropriate community and ethical approvals, such studies will be conducted on volunteers from populations with both high and usual risk for HIV, including those seeking voluntary counseling and testing or healthcare, men who have sex with men and transgender women, HIV-discordant couples, persons who inject drugs, pregnant, neonates, children, adolescents, blood donors, and persons from the general population.